1. Field of the Invention
The present invention relates to the power management for a portable computer system. More particularly, the present invention relates to a method and apparatus for managing the power of a portable computer system, in which a convenient user interface is provided.
2. Description of the Related Art
Users often need to use portable computers in mobile environments. In mobile environments, users do not have access to a typical alternating current (AC) power source for their computers. In this situation, a rechargeable battery is generally used as a power supply instead of an AC power source. The amount of energy stored in a battery is proportional to the weight of the battery. In other words, to store more energy in a battery, the battery's weight inevitably must increase. Thus, a great amount of research has been conducted to improve the energy density and stability of batteries. As a result of such research, nickel cadmium (NiCd) batteries, nickel metal hydride (NiMH) batteries, lithium (Li+) batteries, and lithium polymer batteries have been produced in great numbers. Also, a fuel cell technology is being studied for use in mobile environments as a computer power supply. Although the amount of computing time users are getting in mobile environments can be increased by using a superior battery or many batteries, a battery with a high energy density is expensive and the use of many batteries results in an increase in the weight of a portable computer system. In particular, an increase in the weight of a portable computer system is an obstacle to the main advantage of the portable computer system, its mobility.
Thus, methods for reducing unnecessary power consumption through the power management of a portable computer system are being studied or have been developed. Korean Patent Publication No. 2002-0080615 discloses a method for managing the battery power in a portable computer, in which the length of time a specific function designated by a user can be used with the remaining battery capacity is estimated and displayed through multi-level modes. Additionally, the length of time a specific function can be used is selected or variably controlled by selecting one of the multi-level modes, thereby effectively reducing unnecessary battery power consumption of components that are unimportant when using the specific function and increasing the length of time the specific function can be used.
In Japanese Patent Publication No. 1999-143595, the power capacity of a device capable of setting a power saving mode and the power capacity of a device incapable of setting a power consumption mode are measured. The amount of power consumption by each device is recorded on a recording medium based on results of the measurement, and the recorded values are occasionally updated. Thereafter the power consumption of each device and the power consumption of the device without setting the power saving mode are measured based on the remaining battery power and a power saving setting level obtained from a recording medium. The operation time according to remaining battery power is estimated based on the power consumption of each device and the power consumption of the device without setting the power saving mode and is output.
Such techniques can increase the length of time a portable computer system can use a battery to a degree by preventing the unnecessary use of the battery. However, in most cases, users desire to secure the time required for a specific intended operation through a computer system, for example, one hour of word processing, instead of simply increasing the length of time, for instance, an extra hour and fifteen minutes, the computer system can be used through complicated battery power management. In other words, when users can sufficiently perform a desired operation with the remaining battery capacity, they may not feel the need to manage the power of the portable computer system. Even when power management is required, users may desire to secure the time they can work on computers by simply setting a desired amount of time, for instance, one hour, instead of through complicated selection.
In Korean Patent Publication No. 2001-0096576, upon a user's input of the amount of time required for operating a data processing system, the amount of available power is identified, the amount of power consumed by the data processing system when operating for the input amount of time using the available power is identified, and the amount of power consumption of the data processing system is set to the identified amount of power consumption. Thus, users can use the data processing system for a desired amount of time. However, Korean Patent Publication No. 2001-0096576 does not provide a limit on the amount of time input by users, for example, information indicating that the maximum amount of time input by users is 2 hours. As a result, if users input 3 hours as the amount of time required for operating the data processing system, they only receive a warning message without achieving their goals.
Therefore, it would be beneficial to provide a method and apparatus for managing the power of a portable computer, in which a limit on the amount of time users can use the portable computer and a convenient user interface, are provided.